Quenching apparatus for metallic articles



Jan. 5, 1965 H. N. IPSEN QUENCHING APPARATUS FOR METALLIC ARTICLES Filed Dec. 3l. 1962 3 Sheets-Sheet l JQ-/aroLol Gn- IPJ'eVL.

CHT-vomyf Jan. 5, 1965 H. N. lPsEN 3,164,656

QUENCHING APPARATUS FOR METALLIC ARTICLES Filed Deo. 31. 1962 3 ShAeets-Sheet 2 figs I5 W Il 40 1 l io um Z9 2 n, l I1'? n J 52,s 32' j /43 2 3 26 \2,' 44 '5 l2; /149 1,1 4 4 sz ZS 34. 4 4'? SO 22. so h22? x9 Jan. 5, 1965 H. N. lPsEN 3,164,656

QUENCHING APPARATUS FOR METALLIC ARTICLES Filed Dec. 51, 1962 4 l 3 Sheets-Sheet 3 United States Patent 3,164,656 QUENCHING APPARATUS FOR METALLIC ARTICLES Harold N. Ipsen, Ipsen Industries, Inc., P.O. Box 509, Rockford, Ill.

Filed Dec. 31 1962, Ser. No. 248,664 6 Claims. (Cl. 266-6) This invention relates to quenching apparatus and, more particularly, to yapparatus of the type adapted for use with shaker hearth and other types of furnaces which deliver a substantially continuous flow of heated workpieces to the discharge end ofthe hearth and release these workpieces into a tank ofquenching liquid to be cooled therein as theyl gravitate toward the bottom of the tank.

The primary object of the present invention is to circulate the oil in the tank in a novel manner to maintain a uniform flow of oil at an even temperature across the surfaces of the `gravitating workpieces thereby evenly controlling the rate of cooling of the latter. A more specific object is to provide an upright openended baie substantially enclosing a cooling zone within the tank alongthe precise path of gravitation of the workpieces and to circulate oil at high velocity through the zone transversely of the pathand to a substantial depth.

Another object is to insure that the workpieces gravitate through the cooling zone close to the ports through which the cooled liquid enters the zone.

The invention also resides in the novel manner of circulating and cooling the liquid.` Other objects and advantages'of the invention will become apparent from the following detailed description taken in connection with the accompanying drawings, in which l l FIGURE 1 is a fragmentary side elevational view of a quenching apparatus embodying the novel features of the present invention, the apparatus being shown in conjunction with a portion of a shaker hearth furnace and with parts broken away and shown in section.

FIG. 2 is an enlarged fragmentary sectional view taken along the line 2 2 of FIG. 1.

FIG. 3 is a fragmentary sectional view taken along the line 3-3 of FIG. 2.

FIG. 4 is an enlarged fragmentary perspective view of one of the cooling elements.

FIG. 5 is a fragmentary perspective View of a portion of FIG. 2 schematically illustrating the oil flow through the apparatus.

As shown in the drawings for purposes of illustration, the invention is embodied in a quenching apparatus particularly adapted for use with a heat treating furnace 11 (FIGS. l and 3) of the shaker hearth type in which workpieces 12 to be treated are deposited on the outer end (not shown)`of an elongated hearth 13 (FIG. l) which extends through the heating chamber 14 of the furnace with the inner end of the hearth positioned over a funnel 15 leading to the quenching apparatus. In such furnaces, the hearth is agitated endwise back and forth, lirst'slowly to the right as viewed vin FIG. 1 and then rapidly back, to advance the workpieces stepy by step by inertia along the hearth and through the heating chamber.

When the workpieces reach the inner end of the hearth 13, they have been in the heatinggchamber 14 for a predetermined period of time and have been heated to a preselected conditioning temperature. Then, the heated parts fall `olf the` hearth and into thefunnel y1f5 which leads to a tankj17 containinga body ofA quenching liquid 18 such as oil tobe cooled rapidly as they gravitate through the oil toward the bottom of the tank. In this instance, the workpieces settle onto Vthe lowerend portionofa conveyor 19 and are carried bythe conveyor upwardly and` ice out of the t-ankto be deposited in a suitable container (not shown) for subsequent handling. Usually, a protective atmosphere is maintained in the heating chamber 14 and in the space 20 (FIG. 3) above the quench area in a well known manner to prevent oxidation of the surfaces of the hot workpieces, and oil vapor in the space i 2t) is drawn out by a suitable eductor (not shown).

` In accordance with the present invention, the quenching oil 18 is circulated in a novel manner to insure effective quenching of the workpieces gravitating toward the bottom of the tank 17 by maintaining a uniform flow of oil at `an even temperature across the surfaces of the workpieces whereby the rate of cooling of the workpieces is closely controlled. This is accomplished by providinga substantially enclosed upright cooling zone 21 within the tank 17 along the precise path of gravitation of the workpieces, and carefully controlling the temperature of the oil within this limited zone by circulating oil transversely of the path of the workpieces to a substantial depth `and quickly withdrawing the oil after contact with the work for cooling and recirculation through the'cooling zone.`

To achieve these ends, a walled chamber or baille 22 is supported in the oil 18 below the funnel 15 with an open upper end for receiving the parts falling from the hearth 13 and an open lower end for discharging the parts onto the conveyor 19 after they have passed through the cooling zone 21. At least one cooling element 23 V(FIGS. l, 2 and 4) is immersed in the oil outside the baille and means is provided to withdraw oil from the bale on one side of the path of the parts, circulate this oil past the cooling element to be cooled thereby, and return the cooled oil to the baiile on another side of the path of the parts to iiow across the path to the point of withdrawal.

In the present instance, the baffle 22 comprises an openended box-like structure formed by four upright ,sheet metal walls 24, 25 and 27 joined together along their edges in the manner shown most clearly in FIG. 5,. The baile preferably is supported with the open end somewhat above the level of the oil and adjacent one side wall 28 of the tank, the left-hand wall inthe drawings. The funnel 15 opens into the baiiie somewhat to the right of the left-hand wall 24 of the baille. On the upper edge of the wall 24 is a flange 29 which is inclined upwardly and to the left and abuts against the tank wall 28 to prevent workpieces from dropping between the tank wall and the baille wall 24. The latteris inclined downwardly and to the right from the ange 29 and'thus guides workpieces away from the tank wall and onto the conveyor 19. The remaining bafe wallsare vertically dispose with the exception of the lower end Yportions 3) ofthe opposed side walls 27 which are bent inwardly (see FIG. 5) to taper the lower end portion of the baille for more effective guiding of parts onto the conveyor. The left-hand edge portions of these side walls extend past the inclined wall 24 and areformed with outwardly turned ilanges 31 (FIGS. 2 and 5) secured as by welding to the tank wall 2S to provide a large portion of the support for the baille on the tank.

The means for circulating oil through the baille 22 includes a plurality of inlet ports 32 formed in the inclined wall 24 and an outlet port 33 formed in the opposite wall somewhat above the lower edge ofthe wall.

25 at least partially below the surface of the oil. It is important to note that the inlet ports are vertically spaced alongthe inclined wall from a level adjacent the surface of the oil to a level well'below the surface. Herein, the

inlet ports comprise live horizontally elongated slots punched out of the wall and extending across most of the width of the latter, the uppermost slot being close to the A3)` which are inclined upwaldly and outwardly from the 37 which herein takesthe form of a motor-driven screwV propeller mounted in the bottom of a chamber 38 formed outside the baille and communicating with the interior of the latter through the outlet port 33. The propeller is fast on the lower end of a vertical motor shaft 39 which is'rotated at high, speed by a motor 4t) mounted on the top wall 41 of the tank 17. Thus, in one direction of rotation of the propeller, the blades thereof draw oil through the outlet port and downwardly through the chamber 3S.

The chamber 3.8 is formed by the baille wall 2S on one side, upright sidewalls 42 (FlG. 5) depending from the top wall 41 of the tank, an upright wall 43 (FG. 3) spaced from the baille wall and connecting the edges of the side walls 42, and a horizontal bottom wall 44 (FIGS. 2 and 3) above the lower edges of the side walls and end wall. A tubular sleeve 45 fast in and projecting through the bottom wall 44 encircles the propeller 37 to define a flow passage for carrying'oil out of the chamber V38.

Below the wall 44,Y the llow through the sleeve 45 is split into two lateral flows by a deilector 4'7" of inverted V-shaped cross-section centered below the ring and supported on a horizontal plate 48 spaced below the bottom wall 44 and connecting the lower end of the end wall 43 to the baille wall 25 to form another chamber 49. The right-hand portion $6 of this plate is inclined upwardlyV as shown in FIGS. 3 and 5 to dellect the two lateral flows kto the left (FlG. 3) and under the side walls 42 which terminate above the horizontal portion of the plate 4S thereby forming apertures S1 opening out of the lower chamber 49l to each side.

Another chamber 52 (FIG. 3) is formed on the opposite side of the bafle 22 in the space betweenthe inclined wall 24 and the adjacent wall 28 of the tank, the sides of this chamber being closed by the baille side walls 27. The lower end of the chamber-may beleftkopen'. Oil drawn from the baille by the propeller 37 is carried to this chamber through a passage 53 V(see FlG. 2) communicating between the chamber 52 andV the upper chamber 38 through the lower chamber 49, there being two such passages inthe present instance extending around kthe opposite sides of the baille asshown in FIGS. 2 and 5.

Each passage 53 is formed by three elongated panels 54, 55'and S6 joined together to form an elongated trough of rectangular cross-section open along one side and mounted alongside the baffle 22 with the latter closing the open side along most of its length. Both ends of the trough project beyond the baffle, however, to vopen into opposite sides of the Vlower chamber 49 through ythe apertures 51 at one end and into opposite sides of the chamber 52 at the other end.l The left-hand or outlet ends ofthe passages are enlarged by flaring Vtop and bottom walls 57v formed with flanges secured to the tank wall 28. The right-hand ends of the troughs are closed by plates S (FIG. 5). v' p In this instance a cooling element 23 is disposed in each through the tubes;` Each of these tubes,`therefore, provides a relatively large heat transfer surface to effect rapidl cooling of the oil ilowing laround the tubes.y

VWith the foregoing arrangement', the rotating propeller 37 creates a low pressure area in the upperchamber 38 "to Vdraw oilfrorn the baille 22 through the outlet port 33 into thelow pressurenchamber. The oil then is forced downwardly into the chamber 49 where it is deflected `laterally into and flows through the passages 53 and is cooled therein. The passages discharge the cooled oil into the chamber 52 from both sides of the latter, mixing the two liows and creating a high-pressure area within this chamber. Thus, the oil is forced through the inlet ports 32 in the wall 24 into the low-pressure area created within the baille by the action of the propeller, and llows across the cooling zone 21 toward the outlet port. A relatively high velocity llow of oil through the ports is obtained when the propeller is rotated at high speed.

lt will be seen that heavier workpieces dropped through n the funnel either gravitate'throughthek baffle along paths passing'close to the inclined wall 24 or actually slidedown the wallitself. The upwardly'inclined llanges 34, ofY course, prevent sliding workpieces from falling through the slots and out of the baille. With cooled oil ilowing across the cooling'zone from evenly spaced elongated inlets, the temperature within the cooling zone is evenly controlled to a substantial depth for effective, even quenching of the gravitating parts before they settle on the conveyor. In addition, the transversely flowing oil will carry relatively light workpieces laterally and thereby to some extent prolong the period of time required for Y inlet ports.

passage 53 to cool the oil as itrflowrs through the passage. i

These elements may take the form of continuous tubes extending into and out ofthe troughs through` the'end plates 58 and bent back and forth within the passages A cooling mediumv from a suitable source (not shown) is pumped continuously Vtorforrn twosets of parallel lengths in Vvertically spaced .planes (see FIGS. 2 and 4).

The conveyor 19 is formed by an endless belt' 59 trained around the upper and lower pulleys 6@ and sliding along two spaced guide plates di and 652 which are disposed between the two runs of thebelt and curve upwardly from a generally horizontal attitude below the baille` 2,2k to a fairly sharp incline whichcarries the belt out-of the oil and the tankl at the right-hand end of the latter. The pulleys are mounted on shafts 63 spanning and journaled in two upright side plates 64 which are shaped to follow the path 'of the belt andare disposed on opposite sides thereof. Therbelt is driven in the appropriate direction by a motor 65 (FlG. l) driving an endless chain 66 through a reducer 67 and a sprocket 68, the chain 66 being trained Varound a sprocket 69 rotatable with the upper pulley 6i). v

As shown most clearly in FIGS. 2 and 3, the space 2t) above the quench area of the oil 18 may be sealedo by the plates 27 and the upper portion 74) of thekwall 43. Herein, the upper portion itl comprises'a plate of rectangular cross-section sealed'both to the wallV 43 and to the top wall 41 of the tank.V ln this manner, the controlled-atmosphere space above the ltank is limited to a' relatively small volume and is segregatedl from the area through whichy the conveyor protrudes.Y

lt will be apparentv that the provision of an'upright,

open-ended baille within the quench tank and substantially surrounding the path of'gravitationof the workpieces makes it possible to maintain a zone of even, closelycontrolled temperature to `a 'substantial depth along the path of the workpieces. Y Witha conveyor 19 intheV tank below the baille,` the workpieces are cooled at the desired,

' uniformrate and are removed'fromthe tank without any when used with a furnace of thettype which produces a substantially continuous fiow of heated workpieces which are quenched automatically as they drop from the hearth.

I claim as my invention: Y

1. Quenching apparatus for a controlled atmosphere furnace including, in combination, a tank for holding a body of liquid to a preselected level and having an open top, a baiile supported in said tank and having upright Vside walls substantially enclosing a portion of the liquid in said tank, an open upper end disposed above said level to receive workpieces from said furnace, and an openY lower end spaced above the vbottom of said tank for disin said baffle, a conveyor in said tank having a lower end portion disposed beneath said bafe to receive workpieces gravi-tating through the baiile and an upper end portion extending` upwardly out Vof the tank outside the baffle, means defining inlet and outlet ports in said bafiie spaced apart across the latter, means defining a iiow passage charging workpieces into the tank after the workpieces have gravitated through the liquid in said batlie, a conveyor in said tank having a lower endportion disposed beneath said baiiie to receive workpiecestherefrom and an upper end portion extending upwardly out of the tank outside the baliie to carry the Workpieces out of the tank,

means defining first and second walled chambers on opposite sides of and adjacent said baie and segregated from the remainder of the tank outside the baffle, the wall of d said baffle adjacent said first chamber being formed with an outlet port below said level communicating with the first chamber, and the Wall of said baliie adjacent said second chamber being formed with a plurality of-horizontally elongated and vertically spaced inlet ports belowy said level and communicating with said second chamber,

means defining at least one enclosed passage extending around said baiiie and communicating at its opposite ends with said chambers, cooling means in said passage, an impeller in said first chamber for drawing liquid through said outlet port and forcing the liquid through said passage to becooled and into said second chamber to flow across the interior of said baffle to said outletport, and

means for maintaning a protective atmosphere above the V liquid in said bafe and said chambers.

2. Quenching apparatus for a controlled atmosphere furnace including, in combination, a tank for holding a body of quenching liquid and having an open top, an upright baffle supported in said tank and having an open upper end for receiving workpieces to be quenched from said furnace and an open lower end spaced above the bottom of said tank for discharging workpieces into the tank after the workpieces have'gravitated through the liquid segregated from the liquid in the tank outside the baffle and communicating at its opposite ends with the respectiveports, means for 'inducing a fiow of liquid from'the interior of said b aflle and successively through said outlet port, through said passage, back to said baie through said inlet port, and across the interior of the baie and the path receiving workpeces from the furnace.

4. Quenching apparatus'as defined in claim 2 in which said flow passage includes first and second chambers disposed on opposite'sides of said bafiie and communicating respectively with said outlet port'and said inlet port and d with opposite ends of an intermediate passage extending around one side of said baiiie toA complete the fioW passage. .5. Quenching apparatus as defined in claim 4 in which said flow-inducing means comprises a power-driven im- Y peller mounted in said first chamber to force liquidtherefrom through said intermediatel passage to said second chamber. y l v 6. Quenching apparatus as defined in claim 5 in which a plurality of horizontally elongated inlet ports are vertically spaced along oneside of said baiiie in communcation with said'second chamber.

References Cited in the file of this vpatent UNITED STATES PATENTS Purnell June 29, 1943 Snelson Mar. 15, 1955 

2. QUENCHING APPARATUS FOR A CONTROLLED ATMOSPHERE FURNACE INCLUDING, IN COMBINATION, A TANK FOR HOLDING A BODY OF QUENCHING LIQUID AND HAVING AN OPEN TOP, AN UPRIGHT BAFFLE SUPPORTED IN SAID TANK AND HAVING AN OPEN UPPER END FOR RECEIVING WORKPIECES TO BE QUENCHED FROM SAID FURNACE AND AN OPEN LOWER END SPACED ABOVE THE BOTTOM OF SAID TANK FOR DISCHARGING WORKPIECES INTO THE TANK AFTER THE WORKPIECES HAV GRAVITATED THROUGH THE LIQUID IN SAID BAFFLE, A CONVEYOR IN SAID TANK HAVING A LOWER END PORTION DISPOSED BENEATH SAID BAFFLE TO RECEIVE WORKPIECES GRAVITATING THROUGH THE BAFFLE AND AN UPPER END PORTION EXTENDING UPWARDLY OUT OF THE TANK OUTSIDE THE BAFFLE, MEANS DEFINING INLET AND OUTLET PORTS IN SAID BAFFLE SPACED APART ACROSS THE LATTER, MEANS DEFINING A FLOW PASSAGE SEGREGATED FROM THE LIQUID IN THE TANK OUTSIDE THE BAFFLE AND COMMUNICATING AT ITS OPPOSITE ENDS WITH THE RESPECTIVE PORTS, MEANS FOR INDUCING A FLOW OF LIQUID FROM THE INTERIOR OF SAID BAFFLE AND SUCCESSIVELY THROUGH SAID OUTLET PORT, THROUGH SAID PASSAGE, BACK TO SAID BAFFLE THROUGH SAID INLET PORT, AND ACROSS THE INTERIOR OF THE BAFFLE AND THE PATH OF GRAVITATION OF WORKPIECES TO SAID OUTLET PORT, MEANS FOR COOLING THE LIQUID FLOWING THROUGH SAID PASSAGE, AND MEANS FOR MAINTAINING A PROTECTIVE ATMOSPHERE IN SAID TANK ABOVE SAID BAFFLE AND SEGREGATING THE PROTECTED AREA OF THE TOP OF THE TANK FROM THE AREA THRROUGH WHICH THE UPPER END PORTION OF THE CONVEYOR EXTENDS. 